Swing bridge

A swing bridge (or swing span bridge) is a movable bridge that can be rotated horizontally around a vertical axis. It has as its primary structural support a vertical locating pin and support ring, usually at or near to its center of gravity, about which the swing span (turning span) can then pivot horizontally as shown in the animated illustration to the right.

In its closed position, a swing bridge carrying a road or railway over a river or canal, for example, allows traffic to cross. When a water vessel needs to pass the bridge, road traffic is stopped (usually by traffic signals and barriers), and then motors rotate the bridge horizontally about its pivot point. The typical swing bridge will rotate approximately 90 degrees, or one-quarter turn; however, a bridge which intersects the navigation channel at an oblique angle may be built to rotate only 45 degrees, or one-eighth turn, in order to clear the channel. Small swing bridges as found over narrow canals may be pivoted only at one end, opening as would a gate, but require substantial underground structure to support the pivot.

Advantages

The swing span turned to allow a boat to pass
I Street swing Bridge span turned to allow a boat to pass Sacramento California
BNSF Railroad Bridge 9.6 across the Columbia River in Portland, Oregon, showing the swing-span section turning.
  • As this type requires no counterweights, the complete weight is significantly reduced as compared to other moveable bridges.
  • Where the channel is wide enough for separate traffic directions on each side, the likelihood of vessel-to-vessel collisions is reduced.
  • The central support is often mounted upon a berm along the axis of the watercourse, intended to protect the bridge from watercraft collisions when it is opened. This artificial island forms an excellent construction area for building the moveable span, as the construction will not impede traffic.

Disadvantages

An example of how small swing bridges like this one may be pivoted only at one end, but that does require substantial underground structure to support the pivot. Victoria & Alfred Waterfront, Cape Town.
  • In a symmetrical bridge, the central pier forms a hazard to navigation. Asymmetrical bridges may place the pivot near one side of the channel.
  • Where a wide channel is not available, a large portion of the bridge may be over an area that would be easily spanned by other means.
  • A wide channel will be reduced by the center pivot and foundation.
  • When open, the bridge will have to maintain its own weight as a balanced double cantilever, while when closed and in use for traffic, the live loads will be distributed as in a pair of conventional truss bridges, which may require additional stiffness in some members whose loading will be alternately in compression and tension.
  • If struck from the water near the edge of the span, it may rotate enough to cause safety problems (see Big Bayou Canot rail accident).

Examples

Government Bridge across the Mississippi has a swing section for river traffic traversing Lock and Dam 15

Albania

Argentina

Australia

Belgium

  • Verbindingsbrug, Zeebrugge. Opened in May 2022. With a length of 130 metres and a passage width of 55 metres, it is the longest swing bridge in Europe.

Belize

  • Belize City Swing Bridge, Belize City, Belize. Oldest such bridge in Central America and one of the few manually operated swing bridge in world still in operation. (Restored in the 2000s)

Canada

China

  • Jintang Bridge (Tianjin) [zh], across Hai River in Tianjin

Denmark

  • Lille Langebro Pedestrian double swing bridge crossing the inner harbour at Copenhagen.
  • Naestved Svingbro, Horizontal clearance 42.0m. Carries a 14m-wide trunk road over the Naestved Canal.

Egypt

El Ferdan Railway Bridge in Egypt; the longest swing bridge in the world, runs from the east of the Suez Canal to the west into Sinai. It is left open most of the time to allow sailing ships to pass in the canal, only closing during the passage of trains.

Estonia

  • The Admiral Bridge (Admiralisild) is a pedestrian bridge in Tallinn, Estonia, connecting two parts of the Old City Harbour. It allows access to the Admiralty Pool (Admiraliteedi bassein) for yachts. It became the first swing bridge in Estonia in 2021.

France

  • Le pont tournant rue Dieu, across the Canal Saint-Martin in Paris, is a distinctive location in the 1938 film Hôtel du Nord, and is featured in the opening shot of the film.

Germany

India

Poira-Corjuem Bridge, Goa

Ireland

Italy

The Ponte Girevole San Francesco di Paola in Taranto
  • Ponte Girevole, Taranto (built in 1958, after an 1887 one of similar design but using different materials) – a very unusual type, with two spans that separate at the bridge's center and pivot sideways from the bridge's outer ends.

Latvia

  • Kalpaka Tilts, Liepāja, connecting the city with the former Russian/Soviet port Karosta.

Lithuania

Chain Bridge, Klaipeda
  • Chain Bridge, Klaipeda. Built in 1855 and still working today, this is the only swing bridge in Lithuania. When the bridge is turned, boats and yachts can enter the Castle port. Rotation of the bridge is manual; two people can rotate the bridge.

The Netherlands

The "Abtswoudsebrug", a swing bridge for bikers and pedestrians built in 1979

Many inner cities have swing bridges, since these require less street space than other types of bridges.

New Zealand

(A "swing bridge" in New Zealand refers to a flexible walking track bridge which "swings" as you walk across.)

Panama

Poland

  • A swing bridge at the Giżycko is one of four bridges that cross over the Luczanski Channel. It is one of ten (four still in operation) swing bridges in Poland.
  • A swing bridge in Ustka, which crosses the Słupia River, and is walkable every 20 minutes.

South Africa

The Clocktower Bridge, in Cape Town, starting to close behind a small boat
  • The Clocktower Bridge is a pedestrian swing bridge at the Victoria and Alfred Waterfront in Cape Town.

Taiwan

Great Harbor Bridge in Kaohsiung during its rotation

Ukraine

United Kingdom

Traffic crossing the Northwich Road swing bridge on the Manchester Ship Canal at Stockton Heath, Warrington
Hull Docks branch bridge

In the UK, there is a legal definition in current statute as to what is, or is not a 'swing bridge'

Cross Keys Bridge in Sutton Bridge which carries the A17 over the River Nene in Lincolnshire close to the border with Norfolk.

United States

The former Chincoteague Channel Swing Bridge in Chincoteague, Virginia, now demolished.

The largest double swing-span bridge in the United States is the 3,250 feet (990 m) long, 450 feet (140 m) navigable span, 60 feet (18 m) clearance George P. Coleman Memorial Bridge.

A swing bridge near Belle Glade, Florida
The swing span of the double-deck I Street Bridge, in Sacramento, open for a ship.

Omaha NE Turn Style Bridge is now a historical landmark. Located 86H674H5+98 Used for rail transport. Connecting Council Bluffs, Iowa to downtown Omaha, Nebraska

Uruguay

Carmelo Bridge, Uruguay, during its inauguration in 1912.
  • Carmelo Bridge. Built in 1912 in Carmelo, it is the oldest swing bridge in all of Latin America.
  • Barra del Santa Lucia Bridge. Built in 1925 as a railway bridge, today is used only by pedestrians.

Vietnam

Han River Bridge in the open position
  • Han River Bridge in downtown Da Nang was designed and built by Vietnamese engineers and workers, and opened on 29 March 2000. Featuring a symmetrical cable-stayed steel swing span with a total length of 122.7m rotating on a rim-bearing circular central pier, it is the only swing bridge operating in Vietnam as of 2025.

See also

References

Uses material from the Wikipedia article Swing bridge, released under the CC BY-SA 4.0 license.